Hydraulic pump

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Nov 16, 2009
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Changed oil and filters , then decided to change hydraulic fluid. 11 gallons of kubota fluid 2 filters $330.00. Yikes so i drained all the fluid ,put on new filters , pretty easy. Cranked it back up, and no hydraulics. Figgered an air block, ran it for few minutes no luck. Broke a few lines , no luck. Called everyone i knew, three dealers, still no luck. Dealer sent out a mechanic, no go. He thought dumba$& cattle man cant do shyte. Ended up loading it up and sent it to the dealer.
??? I don't have Kubota. Hopefully an easy fix so the dealer don't sock you a huge bill. I change hydraulic filters. I don't change the fluid. Mmm....maybe that's not possible on a Kubota?
A Kubota what?

Sometimes just a few PSI of air pressure in the fill port will get them going again.

I had a hell of a time on a Ford 3000 after installing a reman pump. Should've prefilled it. Eventually I just had the owner run it for a while, take it up and down some slopes. It did finally take a prime after a little while.
It is a 2006 Kubota M 4900 4 wd. I ran it for probably a total of thirty minutes but couldn't drive it the fel was down. I havee changed the filters without all the fluid , but thought it was probably time to change everything. Probably a $1000.00 mistake.
I'm sorry for your trouble, but please let us know what the outcome is. There's a lot to be learned from these posts if folks will update the fix.
I will definitely let the forum know what was found. I was in the process of rebuilding my pond dam so I need to get it fixed and back on the farm. I checked on the problem on google and it seems like a known problem. lots of people just kept running their machines and it finally primed. my fel was down , so all i could do was to move in reverse.
Sounds like you lost prime at the pump. You can take the inlet pipe off at the pump and dump some oil into the pump.

This might help in the future. This fellow was working on an M4500, but had the same problem.

Problem solved thanks everyone. It was indeed the hydraulic pump needed priming. I don't know how there is a procedure for these, unless a new hydraulic pump draws enough vacuum to fill the filter reservoir. Or like Dave said they are vacuumed. Other wise they are impossible to fill because of the S-bend design and if you do try to fill the filter canister at the pump end it just goes back in to the sump. The canister is much higher than the transmission. The solution which worked for me( may help others) is I backed up to a very steep incline so the transmission was higher than the filter, I cracked the inlet at the pump, some oil came out and the 3 point hydraulic primed up and started to work.
Got my Kubota M 4900 tractor back today. It was a simple air lock. They removed the Fel and drove it for 15 minutesu, no success. Next they took the line off top of pump.They cranked it till fluid flowed. That fixed it.
It would worry me if the pump was ran that long air locked with potentially no oil in the gears. The aluminum and brass doesn't like running dry for very long at all.

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